1. Field of the Invention
Aspects of the present invention relate to a rechargeable battery and a battery module. More particularly, aspects of the present invention relate to a rechargeable battery and a battery module having a spacer to prevent a short circuit between rechargeable batteries.
2. Description of the Related Art
Rechargeable batteries can be repeatedly charged and discharged, unlike primary batteries, which are incapable of being recharged. A low capacity rechargeable battery composed of a single cell is generally used for portable small electronic devices, such as mobile phones, laptop computers, and camcorders. A large capacity rechargeable battery composed of a plurality of cells connected in a form of a pack is widely used to drive motors for hybrid electric vehicles.
Such a rechargeable battery is manufactured in various forms. The representative form of a rechargeable battery is a cylindrical form or a prismatic form.
Such rechargeable batteries are serially connected to form a rechargeable battery module to drive devices that require a large amount of electric power, such as motors for electric vehicles.
A rechargeable battery typically includes an electrode assembly having an anode and a cathode with a separator interposed therebetween, a case that provides a space to house the electrode assembly, and a cap assembly that closes and seals the case.
In a typical rechargeable battery formed in a cylindrical shape, an anode uncoated region and a cathode uncoated region where an active material is not coated are formed at the anode and the cathode of the electrode assembly, respectively. The anode uncoated region and the cathode uncoated region are disposed to face in different directions. A cathode current collecting plate is adhered to the cathode uncoated region, and an anode current collecting plate is adhered to the anode uncoated region. Each of the cathode current collecting plate and the anode current collecting plate is electrically connected to the case or the cap assembly to guide the current to the outside. For example, the cathode electrode current collecting plate may be electrically connected to the case, and the anode current collecting plate may be electrically connected to the cap assembly. Alternatively, the cathode electrode current collecting plate may be electrically connected to the cap assembly, and the anode current collecting plate may be electrically connected to the case.
The case acts as a cathode terminal when the cathode current collecting plate is electrically connected to the case. A cap plate of the cap assembly acts as an anode terminal when the anode current collecting plate is electrically connected to the cap assembly.
When rechargeable batteries are coupled in series, the cap plate of a first rechargeable battery is connected to the case of a second rechargeable battery adjacent to the first rechargeable battery. A spacing member may be used such that the case of the first rechargeable battery is not electrically connected to the case of the second rechargeable battery. The spacing member should be stably fixed to or attached to the case of the rechargeable battery, so that the spacing member is not separated from the case. If the spacing member is separated from the case, a short circuit may be induced between the cases of adjacent rechargeable batteries.
With respect to a rechargeable battery formed in a cylindrical shape, the cap plate is conventionally fixed to the case by a clamping process while the cap assembly is inserted to the case. Thus, the case should have a predetermined thickness to endure an appropriate clamping pressure. However, if the case is excessively thick, the weight of a battery module is high. Thus, performance of a device including the battery module may be reduced. Particularly, if a battery module is used for a movable device, such as an electric vehicle, it is desirable to reduce the weight of the battery module.
The above information disclosed in this Background section is only for the enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.